Apparatus for treating titanium and other metals



Feb. 26, 1963 G. A. PAGONIS APPARATUS FOR TREATING TITANIUM AND OTHER METALS Original Filed May 4, 1955 9 Sheets-Sheet 1 I {u 6 Qn) l 1 I I I MUN-DOW FEE 5 1 wmzj 553m: m N mmz] 2150/; lllll m N mZ U .Um m I N O Feb. 26, 1963 G. A. PAGONIS APPARATUS FOR TREATING TITANIUM AND OTHER METALS 9 Sheets-Sheet 2 Original Filed May 4, 1955 Feb. 26, 1.963 e. A. PAGONIS APPARATUS FOR TREATING TITANIUM AND OTHER METALS 9 Sheets-Sheet 3 Original Filed May 4, 1955 AAA VALVE UNIT 5 INVENTOR 9 Sheets-Sheet 4 G. A. PAGONIS APPARATUS FOR TREATING TITANIUM AND OTHER METALS Original Filed May 4, 1955 Feb. 26, 1963 VALVE UNIT E INVENTOR GEORGE A. PAGONIS 9 Sheets-Sheet 5 G. A. PAGONIS APPARATUS FOR TREATING TITANIUM AND OTHER METALS :IiI;I'|I;I;-|I

u 0 u I v Feb. 26, 1963 Original Filed May 4, 1955 INVENTOR m N O m P E 6 R O E G 9 Sheets-Sheet 6 APPARATUS FOR TREATING TITANIUM AND OTHER METALS Feb. 26, 1963 Original Filed May 4, 1955 INVENTOR GEORGE A. PAGONIS Feb. 26, 1963 A G. A. lfAGONlS 3,079,451

APPARATUS FOR TREATING TITANIUM AND OTHER METALS A Original Filed May 4. 1955 9 Sheets-Sheet 7 v INVENTOR GEORGE A. PAGONIS Feb. 26, 1963 s. A. PAGONIS 3,079,451

APPARATUS FOR TREATING TITANIUM AND OTHER METALS Original Filed May 4. 1955 9 Sheets-Sheet 8 L150 ne IN VENTOR 9 Sheets-Sheet 9 G. A. PAGONIS APPARATUS FOR TREATING TITANIUM AND OTHER METALS Original Filed May 4, 1955 Feb. 26, 1963 VALVE UNIT 6 500+ INVENTOR II-I- 455W 4w I86 5|88 5154 GEORGE A. PAGONIS 5003 VALVE UN\T F United States Patent O v 7 3,079,451 APPARATUS FOR TREATING TITANIUM AND OTHER METALS George A. Pagonis, San Jose, cans, assignor, by mesne assignments, to Light Metals Research Laboratory, Inc, San Jose, Calif., a corporation of California Continuation of application Ser. No. 505,887, May 4, 1955. This application Nov. 24, 1958, Ser. No. 775,994 28 Claims. (Cl. 13-27) This invention relates to a novel continuous multi-s'tage apparatus for producing commercially pure titanium or base alloys of high purity and homogeneous uniformity and comprises a continuation of my copending application entitled, Process for Treating Titanium Metals, Serial No. 505,887, and filed May 4, 19'55, now aban doned.

The invention also pertains to the recovery of titanium scrap, the purification and realloying of the same.

One of the primary objects of this invention is to provide apparatus which will improve the physical, mechanical and chemical properties of present day commercially pure titanium and titanium base alloys through the use of a unique high frequency induction device employing refractories, in order to produce titanium and its base alloys having a high degree of purity and consistent uniformity. I

Additionally, and as a further object of this invention, it is proposed to provide means for recovering titanium scrap metal and to cast ingots, billets, castings or test bars therefrom, the products having a homogeneous uniformity and grain refinement whereby Government agencies, private industries, and national testing associations are en abled to certify and register specifications of commercially pure titanium and titanium base alloys,'the specifications to be of standard compositions resulting in predetermined physical, mechanical and chemical properties of the end products thereby enabling research laboratories to further the improvement and to produce titanium base alloys of higher stability and which will withstand fatigue, stresses and strains at elevated temperatures, thus enabling an earlier evaluation of the titanium and titanium base alloys and hastening its applications in many more fields inviting higher demands and competition to lower the fabricated cost.

The apparatus employed according to the present invention 'makes it possible for men skilled in this art to evaluate titanium and titanium base alloys in such a manner that their use in wider fields may be speedily appreciated, thereby inviting higher commercial demands for such metals and to increase competition between manufacture'rs to bring about lower costs in the fabricated article.

Another object of this invention is to provide commercially pure titanium and its base alloys and a multistage apparatus to purify and alloy titanium while in its molten state through "the introduction of a scavenger composition or improver elements, and to alloy the titanium by this multi-stage apparatus, an achievement which can not be obtained by the present day are melting apparatuses which are of such nature as to prohibit such a pro cedure.

A still further object of this invention is to provide a novel means for loading, neutralizing and preheating titanium sponge metal, ingot or scrap, without necessitating the preprocessing steps of leaching, washing and granulating such metals according to the present day practices pertaining to methods of melting and alloying the aforesaid metals.

It should be further recognized that in addition to the prior art methods presently employed for recovering scrap, wherein it is necessary that the titanium be re- 3,079,451 Patented Feb. 276, 196 3 duced by machining and granulating the same in order to reclaim it, another prior art method requires that the scrap sheet must be welded in order to form an elongated electrode which is used in the arc process for reducing the metal in order to obtain a titaniurn sponge ingot metal melt. Both of these methods are costly and impractical, and through the practice of the present invention the apparatus herein involved completely eliminates the above mentioned operations for the recovery of the scrap, thereby materially reducing the recovery costs.

This invention contemplates as a still further object the provision of crucibles having divisional refractories, the compositions thereof remaining neutral while subjected to elevated temperatures so as to effect no reaction with the melt. In this connection, it is a further object of this invention to provide apparatus of the type to which reference has been made above wherein selected refractory materials are disposed between the divisional refractories for the purpose of increasing the electrical currents produced by induction apparatus for heating the molten metal or melt, and which are employed in conn'ec'tion with the refractory members to increase the speed of penetration of the magnetic field without efi'ecting skin penetration of the refractories.

Also within the purview of this object of the invention is the provision of induction heating means which, through its special construction and location, eliminates all possibility of over-heating the entire crucible liner.

This invention contemplates as a still further object thereof the provision of means in metal treating apparatus for holding and confining neutralizing, scavenger, or improver elements for preheating within the apparatus as well as unique valve means for releasing the neutralizing, scavenger and improver elements for deposit within the apparatus at such time as these materials may be required. V I

As a still further object of this invention, it is proposed to provide a new and novel means for transferring and controlling the how of molten material between two or more adjacent metal treating devices.

It is within the purview of this invention to provide as a further object thereof, the provision of a means for confining and neutralizing the predetermined alloying elements, together with means for neutralizing and preheating the alloyin elements, and means for discharging the predetermined alloying elements into the melt in order to obtain a substantially homogenized melt.

A further object of this invention is to construct an adaptor for pouring under an atmospheric confinement titanium molten material and discharging it into an ingot mold, billets, castings or bars.

It is a still further object of this invention to provide multi-stage metallurgical apparatus of the type referred to supra, the apparatus being adapted for air tight connecti'on between its several component parts, and operated under inert gas atmospheres and vacuum for each complete cycle of operation of the apparatus, the construction of the apparatus being such as to preclude the entry of the ambient atmosphere therein at any stage during the operation thereof.

It is astill further object of this invention to provide metallurgical apparatus of the type generally referred to above, which is relatively inexpensive to manufacture, non-complex in construction and assembly, and extremely durable in use.

Other and further objects and advantages of this invention will become more apparent from a consideration of the following specification when read in conjunction with the annexed drawings, in which:

FIGURE 1 is a diagrammatic representation of metal- 3 lurgical apparatus employed in the present invention for treating titanium or titanium scrap, the apparatus being constructed and arranged in accordance therewith.

FIGURE 2 is a vertical cross-sectional view illustrating the construction of one of the crucibles employed.

FIGURE 3 is a vertical cross-sectional view illustrating the construction of a second crucible constructed for use in the present invention.

FIGURE 4 is a vertical cross-sectional view illustrating the construction and assembly of a third crucible constructed in accordance with this invention.

FIGURE 5 is a horizontal cross-sectional view taken on the line 5-5 of FIGURE 2, looking in the direction of the arrows.

FIGURE 6 is a vertical cross-sectional view of one of the cylindrical conduits and valves connecting and controlling the fioW of molten metal between adjacent crucibles, the view being taken on the vertical plane of line 66 of FIGURE 7, looking in the direction of the arrows.

FIGURE 7 is a vertical cross-sectional view taken on the vertical plane of line 77 of FIGURE 6, looking in the direction of the arrows.

FIGURE 8 is a horizontal cross-sectional view, partly in elevation, taken on the horizontal plane of line 8-'-8 of FIGURE 6, looking in the direction of the arrows.

FIGURE 9 is a vertical cross-sectional view taken on the vertical plane of line 99 of FIGURE 10, looking in the direction of the arrows, and illustrating the details of the valves employed between the crucibles and the ingot molds as is illustrated in FIGURE 11.

FIGURE 10 is a vertical cross-sectional view taken on the vertical plane of the line 10-10 of FIGURE 9, looking in the direction of the arrows.

FIGURE ll is a vertical cross-sectional view taken on the vertical plane of the line 1111 of FIGURE 12, looking in the direction of the arrows, illustrating the connection between the crucibles and the ingot mold.

FIGURE 12 is a horizontal cross-sectional view taken on the horizontal plane of line 1212 of FIGURE 11, looking in the direction of the arrows.

FIGURE 13 illustrates a modified form of the mold illustrated in FIGURE 11.

FIGURE 14 is a fragmentary perspective view of the mold, cap, its flange, and the closure member for the molten metal discharge assembly therefor.

FIGURE 15 is a vertical cross-sectional view, partially in elevation, showing the loading, neutralizing, and preheating apparatus adapted for use in conjunction with the crucible illustrated in FIGURE 2 of the drawings.

FIGURE 16 is a vertical cross-sectional view, partly in elevation, taken on the line 16-46 of FIGURE 15, looking in the direction of the arrows, and illustrating the details of the valve assembly interposed between the charging chamber and the first of the crucibles.

FIGURE 17 is a vertical cross-sectional view of the charging and neutralizing chamber, taken on the vertical plane of line 17--17 of FIGURE 15, looking in the direction of the arrows.

FIGURE 18 is a vertical cross-sectional view taken on the vertical plane of line 18-48 of FIGURE 15, looking in the direction of the arrows.

FIGURE 19 is an exploded perspective view of a container or shell adapted for use in connection with the crucible illustrated in FIGURE 3.

FIGURE 20 is a vertical cross-sectional view of appjalgalrqtus adapted for use in the crucible illustrated in FIG- FIGURE 21 is a fragmentary vertical cross-sectional view of a modified form of a crucible constructed in accordance with the present invention.

FIGURE 22 is a fragmentary vertical cross-sectional view of the discharge side of the crucible constructed in accordance with FIGURE 21.

FIGURE 23 is an enlarged vertical cross-sectional view of the cartridge shown in association with FIGURE 4 of the drawings.

. 4 FIGURE 24 is a fragmentary detail enlarged crosssectional view illustrating the packing and fitting means employed in passing a conduit through a refractory and the outer steel casing of a crucible.

THE CHARGING AND NEUTRALIZING APPARATUS Referring now more specifically to the drawings, reference numeral 30 (see FIGURE 15) designates, in general, a hydraulic jack of conventional design having a hollow cylindrical body 32 in which a piston (not shown) is adapted to reciprocate. The flanged base 34 thereof is bolted at 36 to an end frame plate 38 which is traversed by a plurality of elongated bolts 40 having their respective threaded ends 42 received within tapped openings 44 formed in the radial flange 46 of an end well 48 of an elongated cylindrical conduit 50. The jack 30 is connected, adjacent each end of the body 32, by fittings 52 and flexible hoses 54, with a hydraulic circuit (not shown) including valve control means for exerting, alternately, pressure on the opposite sides of the jack piston to effect the reciprocation thereof.

One end of a piston rod 56 is fixedly secured to the jack piston, while the other end thereof extends through an opening 58 formed in the end wall 48 and terminates within the conduit 50. The opening 58 is enlarged at 58A to accommodate a chevron type gasket 60 and is internally-threaded to receive the externally threaded fitting 62, the latter holding the gasket-60 against displacement.

The other end of the piston rod 56 has a hub 64 of a material ram head 66 fixedly secured thereto, the head 66 being substantially circular in configuration and being adapted for reciprocation within the conduit 50 in response to the movement of the piston for the jack 30. The cylindrical member 50 is constructed of steel and is provided with a substantially rectangular access opening 68 in the upper side thereof which aflordsmeans through which materials to be treated are inserted. A removable closure member 70, also formed of steel and having a substantially rectangular configuration, is provided for the access opening 68, the closure member 70 having a pair of oppositely disposed spaced and upstanding lugs 72 at each end thereof, the lugs being provided with bifurcated ends 74'which are adapted to receive stud bolts 76 mounted on pivot pins 78 fixedly secured in bosses 80 integrally formed with the cylindrical member 50. Wing nuts 82 serve to lock the closure member 70 in its closed position against a substantially rectangular sealing gasket 83.

As illustrated in FIGURE 15, the ram head 66 has been moved to one of its extreme positions and has come to rest at one end of the member 50 at a' point .remote from a port 84 adjacent the other end of the member 50 which.

communicates with an enlarged tapped opening 86, the latter receiving a steel fitting 88 to connect one end of a pipe 90 thereto. The other end of ,the pipe 90 connects with the inlet side of a manually operated valve 92 having its outlet or discharge side thereof connected through pipe 94 with vacuum means (not illustrated).

The other end of the conduit 50 is open and is provided with an outwardly extending radial flange 96 having a plurality of openings 98 extending transversely therethrough in circumferentially spaced relation. These openings are adapted to receive therethrough a plurality of bolts 100 which are threaded into tapped openings 102 formed in the radial flange 104 of a valve housing designated, in general, by the reference numeral 106. The flanges 96 and 104 have interposed therebetween an annular gasket 108 formed of asbestos or other similar materials.

THE VALVE As Will be seen from the drawings, the flange 104 of the valve housing is spaced laterally and outwardly from the outer wall 110 of the housing, the valve housing being substantially hollow and having a rectangular configuration. The outer wall 110 is separated and is held in spaced relation with respect to the substantially circular inner wall 112 by means of a pair of oppositely disposed spaced and substantially parallel side walls 114, 116 which are integrally formed therewith. The lower ends of the side and end walls are closed by an integrally formed end wall 118.

The housing 106 is provided with a central body portion 120 integrally formed therewith which extends between the side walls 114, 116, and is positioned intermediate their respective ends. As is seen in FIGURES and 16, the central body portion 120 is formed with a passage 122 which is coaxially aligned with the cylindrical conduit member 50 and is of the same diameter. The central body portion 120 divides the housing -106 in such a manner as to provide upper and lower cavities 124, 126, respectively.

A substantially rectangular gate valve 128 is mounted for vertical reciprocation through the central body portion between the arms 114, 116. As is seen in FIGURES l5 and 16, the gate valve 128 has a substantially solid upper end section 128A and is provided with an aperture 128B adjacent the lower end thereof of substantially the same diameter as the passage 122. One end of the valve operating rod 128C is integrally connected with the solid upper end portion 128A and projects upwardly through the cavity 124 through an opening 130 formed in the foot portion 132 of a substantially reversed C-shaped cap plate 134. An asbestos gasket 136 is interposed between the foot portion 132 and the upper end of the housing 106, and the latter is provided with a pair of laterally and outwardly extending flanges 114A, 116A integrally formed with the arms 114 and 116, respectively. The cap plate 134 is secured by bolts 138 to the flanges 114A, 116A, the bolts being threaded into the openings 11413 and 116B, respectively. The opening 130 is enlarged to receive a chevron type gasket 140 and a steel fitting 142 through which the rod 128C extends.

The leg portion 144 of the cap 134 is integrally formed with a laterally extending enlarged boss 146 which is provided with a vertically extending passage 148 to receive the upper threaded end 128D of the rod 128C. A valve operating wheel 150 having an internally threaded hub 152 is mounted on the upper end 128D of the rod 128 C. Thus it is seen that as the wheel 150 is rotated in a clockwise direction, the solid portion 128A of the gate valve 128 is moved upwardly into the cavity 124, and in sodoing moves the apertured portion 128B thereof upwardly into coaxial alignment with the passage 122; The arrangement is such that the lower end portion 128E of the valve 128 is never drawn upwardly beyond the lower marginal edge 120A of the central body portion 120.

After the gate valve 128 has been elevated to its open position, counter-clockwise operation of the Wheel 150 will lower the apertured portion 128B into the cavity 126, and the solid portion 128A thereof will move downwardly out of the cavity 124 to extend across the passage 122, the valve 128 now being returned to its normally closed position.

THE PREHEATING APPARATUS An annular asbestos gasket 154 is interposed between the inner wall 112 of the housing 106 and one end of an elongated cylindrical conduit 156. This end of the conduit 156 is provided with a radially and outwardly extending flange 158, and the flange 158, gasket 154, and inner wall 112 of the housing 106 are connected together by means of a plurality of bolts 160. The other end of the cylindrical conduit 156 is also provided with a radially and outwardly extending flange 162 which is connected with the upper end of a cylindrical side wall 164 of a crucible 165 by bolts 166 (see FIGURE 2 of the drawings). A neoprene annular gasket 168 is interposed 6 between the flange 162 and the adjacent portion of the cylindrical side wall 164.

A cylindrical core 170 formed of heat insulating material such as magnesium oxide is telescoped within the conduit 156. The inner circumference of the insulator 170 is formed with a helicoidal groove 172 in which is wound an electric resistance heating element 174, and the ends 174A (see FIGURE 15) and 1743 (reference to FIG- URE 2) thereof are connected to a suitable source of electrical energy in a manner to be described below. It should be noted that the insulator 170 extends from a point adjacent the flange 158 of the conduit 156 to a point inwardly of the cylindrical wall 164 of the crucible 165 and is suitably supported therein by means to be described.

One end of an elongated steel cylindrical pipe 176 is provided with an integrally formed outwardly extending radial flange 178 which is suitably apertured at spaced intervals 180 to permit the passage therethrough of a plurality of bolts 182 for threaded engagement within tapped openings 184 whereby the pipe is fixedly secured to the inner side 112 of the valve housing 106. The inside diameter of the pipe 176 is substantially the same as the passage 122 and the two are coaxially aligned.

Referring to FIGURE 15 of the drawings, it should be observed that the gasket 154 is extended for interpositioning between the adjacent sides of the flange 178 and the inner wall 112 of the valve housing. The pipe 176 is concentrically located with respect to the insulator 170 and is maintained in spaced relation relative thereto to provide a hollow annulus 186, and the other end thereof projects inwardly of the crucible 165 and terminates at a point beyond the insulator 170.

THE FIRST CRUCIBLE The crucible 165 includes the steel cylindrical side wall 164, having an integrally formed bottom wall 188, the upper end of the crucible being open. The upper end of the crucible 165 is provided with an opening which receives and supports therein the insulator .170. A second substantially circular opening 192 extends transversely through the side wall 164 adjacent the bottom wall 188 and is in vertical alignment with the opening 190. A third opening 194 is formed in the side wall 164 diametrically across from-the opening 192, the center point of the opening 194, however, being positioned slightly above the center point of the opening 192. A cylindrical shell 196 formed of a refractory oxide such as Transite (asbestos-cement material) having open upper and lower ends is telescoped within the side wall 164. The upper end of the Transite member terminates at a point adjacent to but spaced from the upper end of the side wall 164 while at points adjacent the lower end thereof the shell is apertured at 198 and 200 for coaxial alignment with the openings 192 and 194. The lower end of the shell rests on the crucible bottom wall 188.

The shell 196 is provided with a helicoidal groove 202 on the inner side thereof which extends intermediate the openings 190 and 198, 200, in which is laid or Otherwise secured a hollow copper coil 204. One end 204A of the coil 204 extends outwardly through an opening 206 formed in the side wall 164 and through the gasket 208 and fitting 210 therefor and is connected with a source of water or other coolant. Lead 212 of one side of a high frequency alternating current source is connected to the exposed end 204A. The other end of the coil, 204B, extends through a similar opening 214 formed in the side wall 164, and gasket and fitting 216 and is connected to the water discharge system. This end of the pipe has fixedly secured thereto the other lead 218 of the high frequency alternating current source.

A vertical elongated hollow cylindrical body 220 is telescoped within the lower end of the shell 196 and is also formed of a refractory oxide such as, for example, Transite, the body 220 being supported on the bottom wall 188. Within the cylindrical body 220 is telescoped a cylindrical disc 222 which is also supported on the bottom wall 188. As is seen in FIGURE 2, the disc 222 is provided with a plurality of transversely extending passageways 224 which register with ports 226 which are enlarged and tapped to receive fittings 228, the latter connecting the ports through branch pipes 230 with a main conduit 232 connected with a source of an inert gas such ashelium, under pressure. Neoprene gaskets 234 may be used, if found necessary, to seal the fittings 228.

A second cylindrical disc 236 formed of a refractory oxide such as, forexample, grog or Transite, is superposed on the soapstone disc 222 and is telescoped within the cylindrical body 220. The disc 236 is provided with a plurality of transversely extending passages 238. The disc 236 is integrally formed with a laterally extending substantially centrally positioned upwardly extending cylindrical boss 236A having an external helicoidal groove 240A formed therein which connects at its lower end with the innermost end of the groove 240.

A conduit 242 has one of its ends connected with a source of water under pressure while the other end thereof connects through. a coupler 244 of conventional design with one end of a copper tubing 246 which extends through a fitting 248, gasket 250 and opening 252 formed in the bottom wall, 188 and. continues upwardly through the communicating passages 254, 256 formed in. the discs 222 and 236, respectively, and is coiled at 246A. in the grooves 240 and 240A. As is seen in FIGURE 2, the convolutions of the coil 246A spiral inwardly of the disc 236 and upwardly along the boss 236A and terminate in an end portion, 246B which extends downwardly through a vertically extending centrally positioned bore 248 coaxially aligned with the boss 236A. The portion 2468 then extends laterally through a passage 236B formed in the disc 236 and then downwardly through a connecting' passage 222A which registers with a discharge port 260. The portion 246B extends through this port, the sealing gasket 262 and fitting 264 for connection with one end of a second conventional coupler 266 having its other end connected with the water discharge system through the conduit 268. Leads 270 and 272 connect the tubing 246, 246A and 246B with a high frequency alternating current source.

The bore 258 at its lower end is in open communication with the coaxially aligned passage 222B formed in the disc 222, and which connects through a discharge port 27 4, a fitting 276' sealed by gasket 278 and the reduced cap fitting 280 with one end of a pipe 282, the other end of which i'sconnected with high vacuum means.

The exposed upper portions of the cylindrical disc 236 and or the convoluti'ons 246A are encased in a layer of a refractory oxide, which extends thereacross and upwardlyovcr the boss 236A. The refractory oxide has a transverse dimension equal to the distance between the upper surface of the'disc 236 and the upper end of the cylindrical bod 220.

An outer cylindrical element 284 is concentrically positioned within the crucible 165 and is formed of a refractory material such as, for example:

(1) 80% thorium dioxide, 10% yttrium trioxide, 10%

zirconium dioxide;

(2) 90% thorium dioxide, 10% yttrium trioxide;

(3) 85% thorium dioxide, 10% hafnium dioxide, 5%

yttrium trioxide;

(4) Carbon graphite which has been impregnated with 90% thorium, hafnium which is then fired to a minimum temperature of 3000 F.

As is seen in FIGURE 2, the lower end of the element is provided with an integrally formed closure wall 286 having a centrally positioned inwardly and upwardly extending concave-convex socket 288 formed therein to receive the boss 236A together with its encasement of refractory oxide.

The element 284 adjacent the lower end thereoi is provided with a transverse bore 290 and counter-bore 292 which are coaxially aligned with the opening 192. Diametrically across from this bore and counter-bore, the element 284 is provided with a second bore. 294 and counter-bore 296 which are coaxially aligned with the opening 194. Vertically spaced from and aligned with the bore 290 and counter-bore 292, the element 284 is formed adjacent its upper end with a third bore 298.

.A plurality of passages 300 extend through the cylindrical element 284, its closure wall 286, and socket portion 288.

The element 284 at its upper endterminates. at a point spaced below the upper end of the side wall 164.

A second or intermediate substantially hollow cylindrical element 302 is concentrically positioned within the first element and is formed of any one of the above referred to refractory materials. As is seen in FIGURE 2, the second element is provided with an integrally formed closure wall 304 having a centrally positioned concaveconvex inwardly extending portion 306 forming a socket in which is received the socket 288.

The first and second elements, 284 and 302, respectively, are held in spaced relation by a layer or lining 308 of molybdenum oxide, its dioxide or the trioxide thereof.

The second element, at its upper end, is flush with the upper end of the first element and the molybdenum oxide liner 308 terminates therebelow to provide space for neoprene sealing ring 310. This element is also provided with a plurality of transversely extending passages 312 formed therein as well as in its closed wall 304 and socket portion 306.

The lower end of the element 302 is provided with a bore 314 and counter-bore 316 which are aligned with the opening 192'. Diametrically across therefrom and at a slightly higher elevation, the lower end of the element 302 is provided with a second bore 318 and counter-bore 320. This bore and its counter-bore are aligned with the opening 194.

The third or inner hollow cylindrical element 322 is disposed within the crucible in concentric spaced relation relative to the first and second thereof. As in the preceding cases, the element 322 is formed of any one of the refractory materials referred to above, including its integrally formed base wall 324 and its concave-convex centrally positioned socket portion 326 which receives therein the socket portion 306 ofthe second or intermediate element.

The element 322 together with the second element 284 are held in spaced relation relative to the intermediate element 302 bya layeror liner 328 of molybdenum oxide, dioxide or the trioxide thereof.

Thev liner 328 terminates below the upper end of the element 322 which is flush with the. upper end of the intermediate element 302 to provide an annular space which receives therein a sealing ring 330.

The. lower end of the element 322 is provided with a bore 332 and counter-bore 334 which is coaxially aligned with the opening 192 and a diametrically opposed bore 336 and counter-bore 338, the center points of which are at a. higher elevation than those of the former, and the bore 336 and counter-bore 338 are coaxially aligned with the opening 194.

The upper end of the element 322 is provided with a bore 340 and counter bore 342 which is coaxially aligned with the opening 190.

A circumferential groove. 344 extends around the upper end of the element, 322 which is in open communication with the; upper end of a plurality of longitudinally extending circumferentially spaced bores 346, the lower ends of which communicate with the upper inner end of inclined bores 348 having their respective lower ends in open communication with the, interior of the element 322.

A plurality of heat insulation bricks 350 are disposed on the top of the cylindrical shell 196 with the. upper end thereof l sh with the. upper ends of thethree elements.

The crucible 165 is completed by forming an aperture or opening 352 in the Transite shell 196 and filling the space between the coil 204 and the adjacent element 284 with refractory oxide 354.

The upper end of the crucible 165 is provided with a disc shaped closure member 356 formed of steel and having a centrally disposed raised dome 358. The disc shaped closure member together with its dome has interfitted therein a liner 360 formed of one of the above referred to refractory materials used in any one of the elements 284, 302 or 322.

A pressure gage 362 having a pressure relief valve 364 associated therewith is threaded through the dome 358 and extends into communication with a port 366 formed in the refractory liner 360. A neoprene gasket 368 seals oif the gage. A radiomatic temperature control 370 is mounted in the dome 358 and extends through the refractory liner 360 for communication with the port 372 formed therein, and the control 370 is sealed off by a neoprene gasket 374. p The refractory liner 360 is held in spaced relation relative to the closure member 256 by a layer or lining of grog material 376 and the liner 360 is also provided with a circumferential groove or channel 378 adapted to register with the groove 344. A gasket 380 formed of neoprene or of a silicon material is interposed between the refractory liner 360 and the upper ends of refractory materials and elements disposed within the crucible 165. At circumferentially spaced intervals, the gasket is provided with ports or slots 382 to connect the groove 344 with the groove 378 to form a closed passage. A source of helium or other inert gas under pressure is connected with one end of a steel pipe 384 while the other end thereof connects through a suitable fitting 386 with an inlet conduit 388 which is, in turn, connected with the groove 378.

Thedorne 358 and the refractory liner 360 are centrally apertured at 390 and 392, respectively, and these apertures are coaxially aligned with a sleeve 394 having a pair of opposed open ends. One end of the sleeve 394 is provided with a radially and outwardly extending flange 396 which is bolted at 3-98 to the dome 358. A neoprene gasket 399 is'interposed between the sleeve 394 and the dome 358.

An elongated substantially hollow cylindrical member 400, formed of the refractory material of the three elements, is disposed within the sleeve 394 in spaced relation relative thereto, -and is supported on a neoprene gasket 402 mounted on the refractory liner 360. As is seen in FIGURE 2, the member 400 extends through the refractory liner 360 and is held in spaced relation from the sleeve by a grog refractory 404. A neoprene gasket 406 extends across the upper ends of the grog liner 404 and the member 400 and receives thereon a circular glass window 408. A circular gasket 410 formed of neoprene material extends around the marginal edge of the window 408 and is interfitted within a larger gasket 412 which is mounted on the upper end of the sleeve 394.

The sleeve 394, adjacent the upper end thereof, is provided with a plurality of integrally formed lugs 414 each of which has pivotally mounted thereon a locking dog 416 which is adapted to pivot upwardly into radially extending slots 418 which extend radially inwardly from the circumference of a circular closure plate 420 positioned on the gaskets 410 and 412. The plate 420 is constructed with a sighting opening 422. Lock nuts 423 threaded on the dogs 416 hold the plate 420 firmly in place.

From FIGURE 2 it is seen that the substantially cylindrical magnesium oxide insulator member 170 extends through the openings 190, 3.52, the refractory bore 298 and is seated in the counter-bore 285 of the refractory element 284. The pipe 176 extends beyond the bore 287 and is coated in the counter-bore 342, the diameter of the pipe being substantially equal to the diameter of the bore 340. The crucible 165 is connected with a dross mold to be described below.

10 THE MOLD As is seen in the drawings, an elongated substantially hollow cylindrical member 424, provided with a pair of oppositely disposed open ends, has one of the ends thereof disposed within the counter-bore 334 formed in the refractory element 322. The internal diameter of the cylindrical member 424 is substantially equal to the diameter of thebore 332, and the cylindrical member 424 is preferably formed of the same refractory material as that of the element 322.

The cylindrical member 424 is surrounded 'by a layer or lining 426 of molybdenum oxide, dioxide or its trioxide and is encased by a second elongated substantially cylindrical member 428 having open ends preferably formed of the same material as the second or intermediate element 302. As is seen in FIGURE 2, one end of the elongated cylindrical member 428 is positioned within the counter-bore 316 formed in the intermediate refractory element 302. The cylindrical member 428 is, in turn, surrounded by another layer of molybdenum oxide, 430), its dioxide or trioxideand is encased within a third elongated substantially hollow tubular member 432 having a pair of opposed open ends. Again referring to FIG- URE 2, it will be seen that one of the ends of the member 432 is received within the counter-bore 292 of the first of the refractory elements 284.

The tubular member 432 is surrounded by a liner 436 formed of refractory oxide, and the latter is en- 1 cased in an elongated cylindrical member 442 formed of a refractory material such as Transite. The member 442 is provided with an axially extending helicoidal groove 438 in which is positioned the convolutions of a copper tube 440. It is seen that the refractory oxide 434 and the Transite cylinder 442 both extend through the opening 192 formed in the side wall 164 of the crucible 165 and terminate inwardly thereof at a point adjacent the outer extremity of the refractory cylindrical member 432.

An elongated tubular conduit 444 having opposed ends surrounds the heat insulator 442 and is provided with the radially and outwardly extending flanges 446, 448 at its opposed ends, respectively(see FIGURES 2 and 11).. A plurality of circumferentially spaced bolts 450 secure the flange 446 to the side Wall 164 of the crucible 165. The flange 446 and the side wall 164 have interposed therebetween a gasket 452 formed of neoprene.

One end of the copper tube 440 extends outwardly through an opening 454 formed in the tubular conduit 444, the opening 454 receiving the usual gasket 456 and fitting 458. A lead 460 from one side of a source of high frequency alternating current is fixedly secured to the end 440A of the tube 440, and the other end 440B thereof (see FIGURE 11) extends outwardly through an opening 462 formed in the tubular conduit 444 adjacent the other end thereof. As before, the opening 462 receives the usual gasket 464 and fitting 466. A lead 468 connects the copper tube 440 with the other side of the above mentioned source of high frequency alternating current.

As is seen in FIGURE 11, the cylindrical heat insulating member 442 and the refractory oxide liner 434 terminate adjacent the other end of the conduit 444. A sealing gasket 472 formed of neoprene or other similar materials extends across the flange 448 and is engaged at its opposi-te side by radial flange 474 of a metal discharge nozzle designated, in general, by the reference numeral 476. Bolts 478 and nuts 480 secure the flanges 448 and 474 together.

The dis-charge nozzle 476 is seen to comprise a substantially hollow cylindrical side Wall 482 which is integrally formed with the flange 474 and with a bottom wall 484. An elongated substantially hollow tubular conduit 486 depends from the bottom wall 484 and is in open communication with the chamber 488 formed in the upper end of the nozzle 476. The side wall 482 is 11 provided with a transversely extending opening 490 through which extend the refractory elements 424, 428 and 432 together with the adjacent portions of their respective molybdenum oxide liners.

The chamber 488 together with the tubular conduit 486 is occupied by a packing 492 in which is formed a downwardly extending passage 494 which opens, at its upper end, in a bore 496 extending inwardly from a side of the packing 492. The bore 496 is counter-bored at 498 and again at 500 in order to receive the staggered ends of the refractory elements 424, 428 and 432, respectively, therein.

A passage 502 is formed in the packing 492, the passage having one of its ends in open communication with the downwardly extending passage 494 and the other end of the passage 502 registers with a port 504 which receives a fitting 506 sealed by gasket 508 and connected with one end of a pipe 510 having its other end connected with a source of helium under pressure. A cover plate 512 extends across the open upper end of the chamber 488 and is secured to the upper end of the side wall 482 by means of bolts 514. The refractory packing 402 adjacent the lower end thereof is recessed at 516 and receives thereunder a substantially circular gasket 518 formed of neoprene. The gasket is supported upon the flange 520 which extends radially and inwardly from the lower end of the tubular conduit 486. The lower end of the downwardly extending passage 494 is provided with a counter-bore 522 which opens into the interior of a mold designated, in general, by the reference numeral 524.

A steel flange 526 surrounds the tubular conduit 486 and is slidably mounted thereon. The flange 526 is substantially annular in configuration, and the inner circumference thereof is provided with a recess 528 in which is disposed a gasket 530 formed of silicon.

The flange 526 has secured to the underside thereof a gasket 532 which is adapted to engage the upper arm 534 of a mold cap 536. The mold cap is provided with a pair of openings 538, 540 which are adapted to receive fittings542 and 544, respectively, which are sealed thereto by gaskets 546. The fittings 542, 544 are set in at an angle in the flange portion 548 of the mold cap 536 and communicate at their inner ends with the inclined passages 550 and 552, respectively.

Referring to FIGURES 11, 12 and 14, it is seen that the mold cap 536 and the mold 524 are substantially circular in configuration. The upper end of the mold 524 is recessed to provide a shoulder 554 on which is disposed a circular gasket 556 formed of neoprene material. The mold 524 is provided with a centrally disposed substantially cylindrical chamber 558 of substantially conventional design. The cylindrical wall 560 of the mold 524 is formed of steel and has embedded therein an elongated helicoidal tubing 562 formed of copper which is tungsten metalized. One end 562A of the tubing 562 is connected with a. source of fluid under pressure such as, for example, water or other coolant, and the other end 5628 is connected with the water discharge system. A pair of diametrically opposed trunnions 564 are fixedly secured to the Wall 560 of the mold 524.

For reasons which will be explained in detail below, the fitting 542 has connected thereto one end of a pipe 566 having its other end connected with a source of helium under pressure. The fitting 544 is connected with one end of a pipe 568 having a pressure relief valve 570 connected therein with a high vacuum source through the pipe 571.

The mold cap 536 is provided with a substantially rectangular slot 572 which extends inwardly from a side thereof in order to receive a valve plate or gate 574 which is adapted to extend across the central opening 576 formed in the mold cap 536. The mold 524, as illustrated in FIGURE 11, is shown in its operative position in connection with the crucible illustrated in FIG- URE 2. 1 The valve 574 has been opened to the position 12 shown in FIGURE 14 and the tubular member 486 has passed therebelow.

When the mold 524 has been filled with molten'material from the crucible illustrated in FIGURE 2, the mold together with its cap is lowered away from the tubular member 486 until the lower end thereof clears the upper side of the slot 572. At this time, the valve 574 is moved to its closed position completely sealing off the opening 576. At this time a substantially cylindrical cap 578 having a handle 580 is inserted over the lower end of the tubular member 486.

Prior to the removal of the mold 524 from the lower end of the tubular member 486, the flow of the metal through the passage 494 is cut off by valve means to be described below.

Attention is directed to FIGURE 13 of the drawings wherein a modified form of the mold 524 is illustrated.

In the modification, reference numeral 582 designates, in.

general, the modified mold which is seen to comprise a pair of inner and outer cylindrical members 584, 586 having closed bottom ends 588'and 590, respectively. The cylindrical members 5'84, 586 are held in concentric spaced relationship by means of a liner 592 formed of a refractory oxide such as Transite and having an axially extending helicoidal groove 594 formed in the inner surface thereof to receive the convolutions 596 of a copper pipe 598. The opposed ends (not shown) of the pipe 598 are connected, respectively, with a source of fiuid;

under pressure and a discharge system.

THE VALVE As has been mentioned above, the valve is connected in the refractory member 424 through the conduit 444 intermediate the crucible and the mold 524. The details of the valve construction are illustrated in FIG- URES 6, 7 and 8 to which reference is now specifically made.

The valve, designated in general by the reference numeral 600, is seen to comprise a substantially hollow elongated substantially cylindrical tubular member 602 formed of any of the refractories mentioned above, the member 602 extending transversely across the inner and intermediate refractory elements 424 and 428. At its lower end, the member 602 is seated within a bore 604,

and the member 602 is provided at its upper end with a flange 606 which seats on a circular shoulder 608 of the counter-bore 610. The member 602 is provided with a horizontal substantially cylindrical bore 612 which is of the same inside diameter as the inside diameter of the refractory element 424 and is coaxially aligned therewith. The member 602 is formed with a substantially rectangular axially extending passage 614 in which is mounted for reciprocation a gate valve 616 formed of any one of the above referred to refractory materials.

The gate 616, as illustrated in FIGURES 6 and 7, is shown in its closed position. By means to be described, the gate valve 616 is adapted to be elevated from the position shown in FIGURES 6 and 7 to effect alignment of a passage 618 with the opening formed in the refractory member 424. A steel grid 620 is embedded in the upper end of the gate valve 616 and is provided with an externally threaded extension 622 which is threaded in a cap 624.

T he lower end 626 of a housing, referred to in general by the reference numeral 628, extends downwardly through the cylindrical conduit 444, the Transite insulator 442, and the refractory oxide 436, and is seated on the upper end of the flange 606. The lower end of the housing 626 issubstantially hollow to permit reciprocation of the cap 624 therein.

As is seen in FIGURE 6 of the drawings, the cap 624 encloses an enlarged substantially cylindrical boss 630 integrally connected with the lower end of the valve stem 632 which is externally threaded at 634 for threaded engagement with the tapped opening 636 formed in the closed end wall 638 of the housing 628. The conduit 444 is provided with a raised boss 640 on which is positioned a flange 642 which extends radially and outwardly of the housing 628. The flange 642 is fixedly secured to the boss 640 by means of stud bolts 644. A gasket 646 is interposed between the flange 642 and the boss 640.

The housing 628 is provided with a substantially hollow upper section 648 which receives the upper end of the stem 632. As shown in FIGURES 6 and 7, the upper end of the stem 632 is encased in an elongated substantially hollow cylindrical sleeve 650 which is surrounded by a helicoidal length of copper tubing 652. The ends 652A and 652B are connected with a source of water pressure and with the water discharge system, respectively.

To serve a function which will be described in detail below, the upper end 648 of the housing has a trausversely extending bore 654 formed therein which is connected through fitting 656 with a conduit 658 which is, in turn, connected with a source of helium under pressure.

The upper end of the housing 628 is formed with an integral flange 660 on which is positioned a gasket 662. A disc 664 is bolted at 666 over the gasket 662, the disc 664 having a hub 668 aperture at 67 to receive the upper end of the stem 632 therethrough. As in previous instances, the stem is enclosed within a gasket 672 and extends through a fitting 674. The upper end of the stem 632 is provided with a manually operated wheel 676 which is keyed at 678 thereto.

Again referring to FIGURES 6 and 7 of the drawings,

it is seen that the copper tube 440 is extended longitudinally of the cylindrical member 442 to present a minimum area thereof to the lower endof the tubular member 602 in order to prevent heat damage thereto.

The above described valve apparatus bears the legend valve unit A and comprises but one of the valve units B, C, D and E, all of identical construction. The apparatus of these valve units all finding identical counter-parts will not be further described.

THE SECOND CRUCIBLE The second crucible is quite similar to the first crucible hereinbefore described, and elements of the second crucible which find their counter-part in the first crucible may be distinguished therefrom by the elevation of their reference numerals and letters by one thousand.

Referring specifically to FIGURE 3 of the drawings, it will be seen that the inner refractory element 1322 is provided with a bore 2000 and is counter-bored at 2002. The second or intermediate refractory element 1302 is bored at 2004 and counter-bored at 2006. In a similar manner, the refractory element 1284 is bored at 2008 and counter-bored at 2010. Refractory oxide shell 1196 is bored at 2012, and the crucible wall 1164 is apertured at 2014.

The valve unit B connects the first crucible 165 with the second crucible 1165. As is seen in FIGURES 2 and 3 of the drawings, one end of the refractory member 424 seats in the counter-bore 338. One end of the refractory 428 is seated in the counter-bore 320 and one end of the refractory 332 is seated in the counter-bore 296. The other ends of these refractories are seated in the counterbores 2002, 2006 and 2010 of the refractory 1165.

The closure member 1356 is constructed as described before with the exception of the provision of a window. As is illustrated in FIGURE 3, the closure member 1356 is provided with an integrally formed substantially hollow and externally threaded boss 2016 which receives therethrough a refractory liner or shell 2018 shouldered at 2020 for engagement and support on the boss 2016. A gasket 2022 is mounted on the shoulder 2020 and is covered by a window or glass 2024. A second gasket 2026 is positioned over the glass 2024 and the same are held in fixed relation by means of an internally threaded cap 2027 having a centrally disposed aperture 2028 formed in the end wall 2030 thereof. The shell 2018 extends 14 downwardly through an opening 2032 formed in the refractory member 1360 and communicates with the interior of the crucible 1165.

The refractory 1360 is formed with a centrally positioned enlarged opening 2034 which registers with a centrally positioned opening 2036 formed in the dome 1358. A valve housing 2038 is mounted on the dome 1358 and is illustrated in enlarged detail in FIGURES 9 and 10. As shown therein, the housing 2038 is seen to comprise an elongated substantially cylindrical member 2040 having a pair of opposed radially and outwardly extending flanges 2042 and 2044 at its opposed ends. Bolts 2046 extend through the openings 2048 formed in the lowermost flange 2044 and are threaded into tapped openings which extend transversely through the dome 1358. A gasket 2050 formed of neoprene is interposed between the flange 2044 and the adjacent portion of the dome 1358.

The flange 2044 is integrally formed with a radially and inwardly extending flange 2052 on which is seated a gasket 2054. The gasket 2054 may be made of neoprene or other similar materials. An elongated substantially hollow cylindrical shell 2056 ,is disposed within the cylindrical member 2040 and is formed with a substantially cylidnrical bore 2058 and counter-bore 2060 at its upper end. The lower end of the shell 2056 is reduced in diameter at 2062 to provide an external radially extending shoulder 2064. As is seen in FIGURE 10 of the drawings, the shoulder 2064 is seated upon the gasket 2054.

Intermediate the top and bottom ends of the cylindrical member 2040, the latter is provided with a pair of spaced parallel substantially rectangular side members 2066, 2 068 which communicate through a substantially rectangular opening 20.70 with the interior of the member 2040. The side members 2066, 2068 are integrally formed with top and bottom members 2072 and 2074, respectively. A substantially rectangular opening 2076 is formed in the refractory 2056 and is in horizontal alignment with the opening 2070. I

As seen in FIGURES 3, 9 and 10, a substantially rectangular gate valve 2078 is mounted for reciprocation in the opening 2076 and in the cavity formed by the side members 2066, 2068 and the top and-bottom members 2072 and 2074. The gate valve 2078 is formed of a refractory material in which has been embedded a grid 2080 formed of steel or other similar materials, the outer end of the grid having fixedly secured thereto an en larged substantially hollow cylindrical boss 20 84. The boss 2084 receives therein the enlarged radially extending flange 2086 integrally formed on one end of a valve stem 2088 having an intermediate portion thereof threaded at 2090. The valve stem 2088 is connected to the boss 2084 by means of the externally threaded bushing 2092 having a diametrically extending tool receiving recess 2094. The valve stem 2088 is threaded in an opening 2096 formed in a cap plate 2098 which is, in turn, bolted at 2100 to a substantially circular radially outwardly extending flange 2102 formed on the outer end of the side members 2066, 2068 and the top and bottom members 2072,2074. As in previous cases a neoprene gasket 2104 is interposed between the flange 2102 and the cap plate 2098.

The cap plate 2098 is integrally formed with a laterally extending substantially hollow cylindrical casing 2106 which surrounds the outer end of the stern 2088 and is provided with an opening 2108 formed in an intermediate wall 2110. The opening 2108 is enlarged at 2112 to receive the usual chevron gasket 2114 and fitting 2116. The extreme outer end of the valve stem 2088 is keyed at 2118 to the hub 2120 of a manually operated valve wheel 2122.

Bolts 2124 extend through the flange 2042 and are threaded into an enlarged disc 2126 which is separated therefrom by means of the neoprene gasket 2128. A

substantially cylindrical housing 2130 is integrally formed with the disc 2126 and is coaxially aligned with the refractory shell 2056.

A flange 2132 extends inwardly of the housing 2130 and has a downwardly depending lip 2134 which is adapted to seat within the counterbore 2060 of the refractory member 2056. The lip 2134 is integrally formed with a second upwardly flared lip 2136 which extends above the disc 2126. A copper coil or tubing 2138 is cast within an aluminum cylinder 2140, the upper end of the tubing 2138 being secured to a source of water or other coolant under pressure. The lower end of the tubing 2138 is connected, as before, with the water or coolant discharge system. The aluminum cylinder is supported in position encircling the housing 2130 by means of a steel plate 2142 which is welded at 2144 to the housing 2130.

Lugs 2146 are integrally formed with or otherwise secured to the housing 2130 in vertical spaced relationship. The lugs 2146 are adapted to serve as guide and spacer means for a condenser envelope or shield 2148 having an elongated substantially hollow cylindrical configuration.

The condenser 2148 is shown in its exploded configuration in FIGURE 19 of the drawings. As illustrated therein the upper end of the condenser 2148 is provided with a plurality of circumferentially spaced tappedopenings 2150 over' which is disposed a substantially cylindrical disc 2152 having bolt holes 2154 extending transversely therethrough. The disc 2152 is provided with a plurality of transversely extending apertures or perforations 2156. The disc 2152 is covered by a wire mesh member: 2158 over which is superimposed an annular. element 2160 having a plurality of circumferentially spaced transversely extending bolt holes 2162 formed therein. Integrally formed with the annular element2160 isa vertically extending handle member 2164. A- plurality'of bolts2166 extend transversely through the opening 2162 formed in the annular element2160 andpasses through interstices formed in the fine wire mesh. member: 2158, the opening 2154 and are threaded into the-tapped opening 2150;

A housing 2168 having a substantially hollow cylindrical configuration surrounds thecylinder 2140 in spaced relation relative thereto. The intervening space. between. the cylinder 2140 and the casing 2168- is filled=.with. a. refractory material such as grog 2170.

As is seen in FIGURE 3 of the drawings, the lower end of the casing 2168- is provided with a. radially and out-.- wardly extending flange 2172 which is bolted at 2174 to. the disc 2126. The flange and the disc areseparated, as before, by a neoprene gasket-2176.

The casing 2168 is provided with upper and lower apertures which receive therethrough the upper and lower ends of the copper tubing 2138. These openings. as well as other openings through casing members to be de-. scribed in the future, will be understood to be sealed by means of the gasket and fitting arrangement illustrated in FIGURE 24. As illustrated therein, the opening Z formed in the metallic member will always be sealed by means of. a chevron type gasket 2178 and will. be maintained in sealed engagement against the pipe or tubing Y by means of an externally threaded fitting 2180.

The upper end of the aluminum cylinder 2140 and the adjacent upper end of the refractory material 2170 are covered by an anular layer of an insulating refractory 2182 having a high permeability such as, soapstone. The gasket 2184 is interposed between the upper end of the casing 2168, the soapstone refractory 2182 and the adjacent end of the housing 2130.

A closure member 2186 having a substantially circular configuration and a dome shaped central portion 2188 is superposed over the gasket 2184. The dome 2188 is provided with an integrally formed liner 2190 which is held in spaced relation relative thereto. The upper end of the liner and dome areprovided with a central-pas- 16 sage 2192 which communicates with a substantially hollow cylindrical boss 2194 which projects upwardly from the dome 2188 and terminates in a substantially radially and outwardly extending flange 2196. A radial flange 2198 is bolted to the flange 2196 by stud bolts 2200.

As in the previous cases, the two flanges are separated by a liner 2202 formed of neoprene or other similar materials. The flange is integrally formed with one end of a substantially tubular conduit 2204 which is connected with a high vacuum source.

The closure member 2186 is provided with a plurality of radially extending slots 2206 which extend inwardly from the circumference thereof and are adapted to receive the dogs 2208 on which are mounted nuts 2210 whereby the closure member 2186 may be firmly locked and sealed against the gasket 2184. The closure member 2186 is also tappedto receive a fitting 2212 which is connected through a conduit 2214' with a source of vacuum. A thermocouple 2216 extends through the casing 2168 and engages the cylindrical member 2140 whereby the temperature of the latter may be quickly and easily ascertained.

Under some circumstances which will be described below, the condenser 2148 is removed and the device illustrated in FIGURE 20 is substituted therefor. A-s illus-- trated, the substitute member comprises an elongated substantially hollow steel casing 2218 integrally formed with a concentrically positioned coaxially'extending'cylindrical member 2220 by means of a bottom wall 2222. A refractory shell 2224 having a helicoidal groove 2226 extending axially thereof is telescoped within'the casing 2218, an electrical resistance element 2228- being disposed within the spiral groove.

Valve unit C connects the lower endofi the crucible 1165 with a second mold of the type illustrated in FIGURES 11', 12, 13- and'14.

Valve unit D connects the crucible 1165 with the upper en'dof the crucible 3165 comprising the-third crucible of the apparatus illustrated in FIGURE-4 of the drawings;

THE THIRD CRUCIBLE With the exception of but a part" of the crucible illustrated'in FIGURE 3, the crucible of FIGURE'4 is identi- Consequently, elements illustrated cal in construction. in FIGURE 4-which-find their counter-part in FIGURE 3- may be distinguished therefrom by the raising of the reference numerals by one thousand.

The only change that-is made between the crucibles of FIGURES 3'and-4 involves that part ofthe apparatus which is positioned above the horizontal gate mounted on the dome of the crucibles.

In the crucible illustrated in FIGURE 4, the upper flange 3022 of the horizontal gate valve 3078 isbol'ted at" 3124-to a substantially circular disc 4000. A substan-- flange 4004 which is fixedly secured to the disc 4000 by bolts 4006. As in the previous cases, the flange 4004 has a neoprene gasket 4008 interposed between it and adjacent portions of the disc 4000. A substantially hollow elongated cylinder 4010 projects upwardly from' the disc 4000 and is integrally formed therewith. The lower end of the cylinder 4010 is surrounded by an annular ring 4012' of fused magnesium oxide, and the annular member rests upon the upper side of disc 4000.

A core 4014 formed of Transite material is telescoped within the housing 4002 and is supported on the annular member 4012. A plurality of heat insulating brick 4016 are disposed in a ring surrounding the cylindrical member 4010 in circumferentially spaced relation thereto. The innermost side of the brick 4016 is provided with a helicoidal groove 4018 in which is disposed a resistance heating element 4020. The upper ends of the insulating 1 brick 4016 and the Transite 4014 are flush with each other 17 and are covered by an annular member 4022 formed of soapstone or other materials having a high permeability.

The cylindrical member 4010 has a radially and outwardly extending flange 4024 adjacent the upper end thereof over which is superimposed a flange 4026 integrally formed with the housing 4002. The upper end of the cylindrical member 4010 is provided with a plurality of circumferentially spaced lugs 4028 on which are pivotally mounted a plurality of dogs 4030 which are adapted to be swung upwardly into engagement with slots 4032 which extend radially and inwardly from the circumference of a closure member 4034. The closure member 4034 is domed at 4036 and provided with a reduced neck extension 4038 which terminates in a radically and outwardly extending flange 4040.

A gasket 4042 is superimposed on the flange 4040, and the latter is abutted by a flange 4044 integrally formed with a vacuum pipe 4046. The assembly is retained in fixed position by means of a plurality of bolts 4048 which extend through the flange 4044 and the gasket 4042 for threaded engagement with the flange 4040. The closure member 4034 is retained in the position shown by means of the dogs 4030 and the nuts 4031.

Bolts 4050 extend through the flange 4026 and a gasket 4052 for threaded engagement with the flange 4024. A depending boss 4054 integrally formed with the disc 4000 is seated within the counter-bore 3060 formed in the upper end of the substantially cylindrical refractory member 3056.

A cartridge 4060 is disposed within the cylindrical member 4010 with the lower end thereof normally engaging against the gate valve 3078. A pair of upper and lower thermocouples 4080 and 4082, respectively, extend through the housing 4002 and engage against the brick 4016. A fitting 4084 connects the conduit 4006 with a high vacuum source.

THE MODIFIED CRUCIBLE FIGURE 21 illustrates a modified form of the crucible. As illustrated therein the crucible designated, in general, by the reference numeral 5000 comprises an outer hollow cylindrical member 5002 having an integrally formed bottom wall 5004. A ring 5006 formed of an insulating material, such as fused magnesium oxide, is telescoped within the cylindrical side wall 5002 and rests upon the bottom wall 5004. A substantially hollow cylindrical shell 5008 formed of Transite is telescoped Within the cylindrical wall 5002 and rests upon the ring 5006. The shell 5000 is apertured at 5010, the aperture 5010 being coaxially aligned with an aperture 5012 formed in the cylindrical member 5002.

A disc 5014 formed of soapstone is telescoped within the ring of fused magnesium oxide 5006 and rests upon the bottom Wall 5004 of the crucible 5000. As is illustrated in FIGURE 21 of the drawings, the upper side of the soapstone disc 5014 is provided with a centrally positioned semi-spherical depression 5016. A layer of grog material 5018 is supported on the soapstonee disc 5014, the layer of grog material following the contour of the upper side of the disc 5014. As illustrated in FIGURE 21, the upper side of the grog layer 5018 is formed with a helicoidal groove 5020 in which is laid a substantially hollow copper tubing 5022.

A layer of norblack 5024 is superimposed over the tubing 5022 and the grog 501-8, the norblack following the contour of the upper side of the grog material 5018'. A ring 5026 formed of Transite material is positioned in a circumferential groove 5028 formed in the norblack material 5024, the ring being provided with a plurality of openings 5030 which receive the necked-down portion 5032 of an elongated vertically extending cylindrical standard 5034.

As seen in FIGURE 21 of the drawings, the standard 5034 extends through a transversely extending passage 5036 formed in the norblack 5024, the transversely'extending passage 5038 formed in the grog material 5018 and the passage 5040 formed in the soapstone disc 5014. The standard 5034 projects outwardly and downwardly from the bottom wall 5004 of the crucible 5000 through an enlarged substantially hollow internally threaded boss 5042. The outer end of the boss 5042 is sealed by a gasket 5044 and the standards 5034 are held in adjusted relation by means of the nuts 5046 which are threaded on the exposed outer ends of the standards 5034.

A hollow cylindrical refractory element 5048 having a bottom Wall 5050 integrally formed therewith is supported upon the upper side of the Transite ring 5026 and the refractory oxide 5024. The bottom wall 5050 is seen to follow the configuration of the upper side of these elements. The refractory element 5048 is seen to be spaced from the Transite member 5008 and this space is filled with refractory oxide 5052. An inner refractory element 5054 is disposed concentrically within the refractory element 504-0 and is provided with an integrally formed bottom Wall 5056. The bottom wall 5056 of the inner refractory 5054 follows the contour of the bottom wall 5050. The refractory element 5054 is spaced from the refractory element 504% by a layer of molybdenum oxide, dioxide or trioxide 5058.

As in the case of the previously discussed crucibles the innermost of the refractory elements 5054 are provided with a plurality of longitudinally extending passages 5060 which are connected at their upper ends with a source of helium under pressure. The passages 5060 communicate at their lower ends with a horizontally extending passage 5062 and discharge through ports 5064 in the concave base 5066 of the bottom wall 5056.

Adjacent the upper end of the crucible 5000, the refractory element 5048 is provided with a bore 5068 and a counter-bore 5070. The refractory element 5054 is bored at 5072 and counter-bored at 5074. The bore and counter-bore 5072, 5074 are coaxially aligned with the bore 506% and the counter-bore 5070.

The valve units F and G illustrated in FIGURE 2 1 are identically constructed with respect to the valve units A, B, C, D and E disclosed above, with the exception that the valve units F and G employ one less refractory member. As illustrated in the drawings, the valve units F and G are seen to comprise an elongated substantially hollow tubular conduit 5076 having a pair of opposed open ends. One end of the valve units F and G is provided with an outwardly and radially extending flange 5070 which is integrally formed therewith and is bolted at 5080 to the crucible wall 5002. A neoprene gasket 5082 is interposed therebetween.

An elongated tubular member 5084 formed of Transite is telescoped Within the conduit 5076, and has mounted therein a copper coil 5000. Refractory oxide 5086 encases an elongated tubular refractory element 5090 which is spaced from a second elongated tubular refractory member 5092 by a layer of molybdenum oxide, dioxide, or its trioxide 5094. The tubing 5088 connects through its end 5000A with a water discharge system, while the other end thereof (not shown) is connected with a source of Water or other coolant under pressure. The valve of each of the valve units F and G is identical to the valves of the units A, B, C, D and E.

The outer end of the Transite member 5084 extends through the opening 5010 in abutting relationship relative to the refractory element 5048. The outer end of the refractory element 5090 is seated in the counter-bore 5070 and the centrally disposed refractory element 5092 is seated in the counter-bore 5074 in coaxial alignment with the bore 5072. The construction and connection of the valve unit G at the discharge end of the crucible 5000 is identical to that previously described, and a reiteration thereof will not be made at this point.

The discharge valve unit G may be connected with a second crucible identically constructed with respect to the crucible 5000, or it may be connected with a mold designated, in general, by the reference numeral 50%. As seen in FIGURE 22, the other end of the conduit 5076 of the valve unit G is provided with a radially and outwardly extending flange 50% which is connected by bolts 5M0 with a radial flange 5102 of a housing designated, in general, by the reference numeral 51%. The flanges 5098 and 5102 are separated by a gasket 5166 formed of neoprene or other similar material.

Housing 5104 includes a radial flange 5108 integrally formed with the flange 5102 to which is bolted at 5110 a flange 5112 of a dome-shaped cover 5114-. An elongated tubular conduit 5116 depends from the flange 5108 and the conduit and the housing is provided with a refractory member 5118 in which is inserted the outer ends of the refractory elements 5090 and 5092. The ends of the refractory elements 5090 and 5092 are sealed by a refractory cement 5120 and 5122. The refractory member 5118 is provided with a passage 5124 which extends downwardly through the tubular conduit 5-116. The refractory 5118 is also provided with a passage 512.6 which connects through a fitting 5128 with one end of a tube or pipe 5130 connected with a source of helium under pressure.

In its operative position, the depending tubular member 5116 receives a flange 5132 which is slidably mounted thereon and sealed by a gasket 5134 thereto. The underside of the flange 5132 has cemented thereto a neoprene gasket 5136 which normally engages the upper end of the mold cover 5138. The mold cover 5135 is connected through a pipe 5140 and valve 5142 with a source of helium or other inert gas under pressure by means of the fitting 5144- and tubular passage 5146. The cover also connects through a tube 5148 and two-way valve 5150 with a source of vacuum 5152 or pipe 5154 with the recovery side of the helium supply. Fitting 5156 and passsage 5158 connect the pipe 5148 with the interior of the mold 5096, the usual neoprene gasket 5160 is interposed between the mold 5096 and the cover 5138. Coolant is supplied to the mold through the tubing 5162 connected with a source of water or other similar liquids through the conduit 5164. It will be recognized that the mold 50%, the cap 5138, and its associated elements, including the valve 5166, are identical in construction and function as is the mold illustrated in FIGURES 11 and 14 of the above described apparatus.

Leads 5168 and 5 170 connect the tube 5088 with a source of alternating current, and similar leads 5172 and 5174 also connect the tube 5022 with a source of alternating current.

Pipe 5 176 has one of its ends connected with a vacuum source through a two-way valve 5177, while the other end thereof connects through a fitting 5178 and port 5180 formed in the bottom wall 5004 with a passage 5182 formed in the soapstone disc 5014. One end of the pipe 5184 is connected with a source of helium under pressure and connects with a port 5186 through fitting 5188 with a passage 5190 which also extends through the soapstone disc 50 14.

An arcuately-shaped bar 5092 supports the depressed dome 5050A of the bottom wall 5050 by means of the standard 5194 which extends downwardly therefrom and through a boss 5196 for threaded engagement with a nut 5 158. The boss 5196 includes a gasket 5200.

Operation of the Apparatus To effect a complete understanding of this invention, the function and operation of the component parts there- 'of will now be completely described. It should be carefully noted that if the apparatus is operated in accordance with the method of this invention the apparatus will continuously produce ingots, billets and castings of extreme purity and of constant homogeneous uniformity and grain refinement. It will also be found through the practice of this invention that titanium alloys produced thereby will be characterized by improved mechanical, physical and chemical properties. The improvement achieved in producing ingots, billets and castings prepared according to this method will be found far superior than the prior art counter-parts thereof.

For the purpose of illustration, it will be assumed that the equipment has been set up in the manner described hereinbefore, and one complete cycle of the operation of this apparatus will now be described.

The crucible 165 has the closure member 356 thereof removed and the crucible 165 is then filled substantially to the opening or bore 340 with commercially pure titanium sponge or an ingot thereof. It is a Well known fact that commercially pure titanium bears with it certain undesirable elements of varying percentages. These elements generally comprise oxygen, nitrogen, carbon and iron. In this example of operation, let it be assumed that the commercially pure titanium employed has an oxygen content of 0.20%, a nitrogen content of 0.39%, a carbon content of 0.064%, and an iron content of 0.12%. The tested Brinell hardness was 269.

The closure member 356 is now replaced and the dogs 35'? are swung into place in the slots 359 formed in its marginal edge. The nuts 361 are then tightened down to completely seal the crucible 165.

The valve 2078 of the crucible 1165 is moved to its closed position, the dome or closure member 2186 is removed, and the condenser sleeve 2143 is removed from the upper end of the crucible 1165.

A cartridge 2167 (see FIGURE 23) containing and formed of predetermined amounts of scavenger or improver materials is now seated on the valve 2073. The condenser sleeve 2148 is now replaced in the position shown in FIGURE 3, and the closure member 2186 is now tightly locked on the dogs 2203 and the nuts 2210.

The valve 3078 of the crucible 3165 is moved to its closed position as illustrated in FIGURE 4 of the drawings, and the closure cap or dome 4034 is removed to permit the insertion of a cartridge 4066 which is formed of predetermined values of alloying materials. The cartridge 4066 is seated on the valve 3078 and the closure member 4034 is then sealed to the upper end of the casing by means of dogs 4030.

At this point it would be advantageous to specify with particularity the compositions of the scavenger or improver materials and the alloying materials for use in treating commercially pure titanium of the type described above. It has been found that the scavenger materials may comprise the following, the percentages being given by weight:

Metallic calcium Potassium permanganate The lithium and silicon are alloyed in equal parts of each of the metals, the metals being mixed together and melted to form the alloy which will be employed as one of the scavenger agents. In a similar manner, the magnesium and the cerium are alloyed, of the alloy comprising pure magnesium as a base, and 5% thereof the cerium being used as the alloying material. Other scavengers or improvers are potassium permanganate and metallic calcium. The cartridge 2167 and its cover 2169 are for-med of metallic manganese.

All of the above mentioned scavenger and improver metals should be in their purest form, and the elements confined within the cartridge 2167 should be in their granulated form. The contained materials referred to above appear in the following quantities:

tlercent Lithium silicon alloy 0.25

The alloying cartridge 41166 is formed of chrome and encloses alloying elements of molybdenum and iron. The enclosed or encased materials comprise 2.10% molybdenum and 2.0% iron. The chrome cartridge 4066, including its cover is 2.06% of the weight of the melt.

The valves of the valve units A, B, C, D and E, together with the valve 128, are now moved to their closed position.

The closure member 70 is now removed from the conduit 50 and the conduit 50 is filled with a charge of the titanium material which is of the same composition as the material within the crucible 165. The cover 70 is now replaced and locked by the wing nuts 82 against the gasket 83.

All of the apparatus, including the molds, is now connected with a high vacuum source. Thereafter, the vacum is trned off from the crucibles, the molds and the preheating furnace and helium is then supplied thereto, the helium being first passed through a helium purifier 60011. The purifier 6000 is of conventional design and construction. For the optimum operating conditions, the helium should be passed through the apparatus at a pressure of substantially three to five pounds per square inch. The heating elements "of the preheating apparatus 156 and the crucibles 165, 1 165 and 3165 are now energized, and the preheating apparatus is heated to a temperature of 1900 F.; the first of the three crucibles, as is illustrated in FIGURE 2 of the drawings, is heated to a temperature of 3240 F., the melting temperature of titanium; the crucible illustrated in FIGURE 3 of the drawings is heated to 3000 F.; and the crucible illustrated in FIG- URE 4- of the drawings is heated to 3000 F.

It is to be understood that all of the refractories of the preheating apparatus and the crucibles are thoroughly heliumized.

With the apparatus so conditioned, the valve 128 is opened and the ram head 66 is actuated by the hydraulic jack 31 to force a first charge of titanium into the preheating apparatus. The valve 123 is closed and immediately thereafter a second charge of the titanium metal is placed within the charging conduit 50 and the closure member 71) is again rescaled in its respective position. Vacuum is again applied to the charging conduit 50.

At this point it is well to note that vacuum is employcd in conjunction with the charging conduit in order to remove the ambient atmosphere therefrom, as well as to draw from the metal any loose dross or contaminants that may adhere to the titanium charge.

The titanium metal in the crucible 165 is brought to its molten stage and the operator may observe the condition of the melt at any time through the window 408. The temperature of the metal melt being very critical, it is carefully controlled by the radiomatic device 3'70 in order to preclude the inadvertent or accidental over heating thereof. When the metal reaches the critical temperature of 3240 F., the valve 128 is elevated to bring its aperture or opening 122 into alignment with the charging cylinder 50 and the preheating apparatus and the hydraulic jack 30 is then actuated to move from the position shown in FIGURE 15 toward the right of the conduit 50 and in so moving forces the second charge against the first charge disposed in the preheating chamber, causing the first charge to be ejected through the port or bore 340 and to fall into the crucible 165. The valve 128 is then moved to its lowermost or closed position and subsequently the closure member 70 is again removed in order that a third charge may be placed in the conduit 50. As before, the charging conduit 50 is again placed under a vacuum for the purpose and reasons heretofore described.

Assuming that a desired quantity of metal has now been melted in the crucible 165, the valve of the valve unit B is now opened to permit the metal to pass through the opening 366 and the refractory 424 and to discharge into the upper end of the crucible 1165 illustrated in FIGURE 3 of the drawings, through the opening 20150.

As has been previously mentioned, this crucible 1165 has been preheated to a temperature of 3000 F. The metal discharged through the port 26% substantially fills the crucible 1165. At this time the valve of the valve unit B is moved to its closed position. The crucible is recharged with additional material from the charging conduit 50 and the preheating chamber 156 until it has been refilled.

The crucible 1165 with its charge now standing at 3000 F. is supplied with helium under pressure which is discharged through the conduits 1346 and 1348, the helium eifecting an agitation action through the molten melt. The condenser 2143, by heat of conduction, has been elevated at this time to a temperature of substantially 1000 F.

The helium which is passed directly to the interior of the crucible 1165 through the aforementioned passages is now turned down to a minimum pressure, while the helium under pressure at other points throughout the furnace is completely out off. The conduit 1282 is now connected with a source of high vacuum, and the valve 21178 is then cracked slightly.

The helium is permitted to bubble through the melt for a period of approximately three minutes, and the vacuum within the casing 2130 of the crucible 1165 is measured by conventional monometer (not shown) and brought down to 0.10 mm. of mercury. The valve 21178 is then completely opened to permit the cartridge 2167 and its cap 2169 to drop into the crucible 1165. The scavengers now enact with the titanium melt and effect the following action.

When the cartridge 2167, and its cap 2169, are released, they drop downwardly through the mass of molten titanium and come to rest at the bottom of the crucible wall 1326. The cartridge becomes consumed under the melt and gases are released from the scavenger or improver elements which permeate the mass of molten titanium. The scavenger or improver elements combine with or entrain with the carbon, nitrogen, oxygen at the surface of the melt and are picked up by the high vacuum connected with the pipe 22114, and these are condensed on the inner wall of the condenser 2148. The coolant in tubing 2138 effects the crystallization of some of the sublimating elements while the vapor molecules are exhausted to the atmosphere.

After this operation has taken place, the valve 21178 is closed and the furnace vacuum to the pipe 1282 at the bottom of the crucible 11 65 is cut off and the helium supplied through pipes 1230 at the base thereof is turned on and brought up to about three pounds pressure, while the helium to the interior of the crucible through the passages 1346 and 1348 is completely shut off.

The metal is then permitted to rest from five to eight minutes, at which time the now purified titanium metal may be drawn off to a third crucible 3165 for further metallurgical treatment or sampling.

The valve of the valve unit D is now open to transfer the purified molten titanium to the crucible 3165. With this accomplished, the valve of the valve unit D is again closed, sealing off the crucibles 1165 and 3165. The dross or residue material remaining in the crucible 1165 is then drained into the mold .1524 after the valve of the valve unit C has been opened. After the transfer has been accomplished between the crucible 1165 and the mold, the valve of the valve unit C is again closed.

The interior of the crucible 1165 is again connected with a source of helium under pressure through the pipe 1384 after receiving a new melt from the crucible 165.

Sampling of the now purified melt may now be made 

1. A CRICIBLE FOR THE METALLURGICAL TREATMENT OF METALS COMPRISING A CASING HAVING OPPOSED OPEN AND CLOSED ENDS, A REFRACTORY BASE FORMED OF PERMEABLE MATERIAL DISPOSED WITHIN SAID CASING ADJACENT THE CLOSED END, INDUCTION HEATING MEANS DISPOSED ON SID BASE, SAID INDUCTION HEATING MEANS HAVING A COVER THEREFOR FORMED OF A REFRACTORY MATERIAL, AN ELONGATED SUBSTANTIALLY HOLLOW ELEMENT HAVING OPPOSED OPEN AND CLOSED ENDS DISPOSED WITHIN SAID CASING WITH SAID CLOSED END ABUTTING SAID COVER, A CLOSURE MEMBER FOR SAID OPEN END OF SAID CASING, MEANS RELEASABLY SECURING SAID CLOSURE MEMBER TO SAID CASING, SAID CASING AND SAID ELEMENT HAVING A METAL CHARGING OPENING FORMED THEREIN ADJACENT THEIR RESPECTIVE UPPER ENDS, SAID CASING AD SAID ELEMENT HAVING SECOND OPENINGS FORMED THEREIN ADJACENT THEIR RESPECTIVE CLOSED ENDS, MEANS CONNECTED WITH SAID SECOND OPENINGS FOR DISCHARGING MOLTEN METAL FROM SAID CRUIBLE, AND SAID CASIING AND SAID ELEMENT EACH HAVING THIRD OPENINGS FORMED THEREIN IN VERTICALLY AND LATERALLY SPACED RELATION RELATIVE TO SAID SECOND OPENINGS IN SAID CASING AND SAID ELEMENT, AND MEANS CONNECTED WITH SAID THIRD OPENINGS 